Answer:
(1). Both compounds are constitutional isomers.
(2). Both Compounds are constitutional isomers.
(3). Both compounds are identical isomers.
Step-by-step explanation:
NB: Kindly check the attached picture for the diagram paired compounds.
The term 'constitutional isomers' means the isomers with the same molecular formula, the only difference is the way they are arrange. Constitutional isomers have the same number of elements in them, only their arrangements differs.
Constitutional isomers is also known as structural isomers and it is one of the types of isomers. The other one is stereo-isomers or spartial isomers which is also further divided.
Now, let's consider the paired chemical compounds.
(1). Both compounds are constitutional isomers.
Deduction: this are functional isomers as what differs is the arrangement of the C=O group.
(2). Both Compounds are constitutional isomers.
Deduction: the OH group is in the same position. Only the arrangement of carbon differs.
(3). Both compounds are identical isomers.